I feed (water with nutrients added) every other watering. I'm in fabric pots as well, I'm at every other day at this point in the heat. Due to the heat, and my work schedule, the plants have been letting me know when I get home that it's time to water. All a bit droopy this afternoon, where they were very perky this morning.
*As for every 5-7days, I'm not quite sure I could understand a situation where that could be the schedule. At most, I think I made it 4-5days after my last transplant. After which, it has decreased to the routine now.*